The present invention relates generally to homokinetic universal joints and more particularly to a method and structural arrangement whereby a drive sleeve may be fitted about the outer joint member of the assembly.
Homokinetic universal joint assemblies of the type to which the present invention relates are normally formed with an inner joint member and an outer joint member surrounding the inner joint member. Torque transmitting means, particularly spherical balls, are interposed between the inner and outer joint member to effect torque transmission therebetween. Grooves arranged in pairs on the outer surface of the inner joint member and complementary grooves formed on the interior of the outer joint member operate to receive therein the torque transmitting balls in operative engagement. A cage member may also be provided to support the torque transmitting balls and a tubular drive sleeve is mounted about the outer surface of the outer joint member in fixed torque-transmitting engagement.
In known homokinetic universal joints of the prior art, for example of the type described in German Pat. No. 2,121,417, axial grooves are formed in the outer surface of the outer joint member and a circumferential groove is formed in an end region which is reinforced from within. However, the axial grooves are each provided between two adjacent grooves which serve to receive the balls of the assembly. In such an outer joint member it is not possible to effect formation of additional grooves in the outer surface in the region of the grooves, inasmuch as it is rather difficult to harden the metal part because of its shape. In order to avoid such distortions from hardening, the axial grooves in such a joint as well as the circumferential grooves are arranged in the region of the reinforced end.
It will be apparent that in order to form such grooves, exact manufacturing operations are required. Also, in order to press a tubular drive sleeve into indentations for mounting the sleeve there must be utilized a pressing tool which is especially provided for the purpose involved. A further disadvantage arises by virtue of the fact that the outer diameter of the outer joint member and the inner diameter of the tubular sleeve which is to be connected thereto are subject to very narrow and exact tolerances since exact centering of the entire homokinetic universal joint will depend upon adherence to such tolerances. Deformation of the material of the drive sleeve into the grooves is effected by stretching portions of the body of the drive sleeve. In order to enable fastening of a sealing boot onto the joint assembly, an additional ring of sheet material or a pipe clamp must be provided.
In view of the foregoing, the present invention is directed toward provision of a homokinetic universal joint assembly wherein a tubular drive sleeve may be inexpensively and economically connected while simultaneously effecting fastening of a sealing boot without requiring careful consideration of diameter tolerances of the components to be connected, with joint members of different widths and with different shape of grooves being sufficiently fixed. The invention is also directed toward a method for effecting the desired connections.